1. Boil the walnuts for 2 minutes, remove from the water and let them dry.
2. In a pan heat water, honey, vanilla and juice and bring to the boil while stirring. When the honey is dissolved, add walnuts to the syrup and gently stir. Let the wet walnuts rest overnight.
3. Rinse blackberries and blueberries and cut the Castello Danablu into slices – finish with wet walnuts and a drizzle of syrup.